A general pressure sensitive adhesive sheet is constituted by a substrate, a pressure sensitive adhesive layer formed on the substrate, and a release material provided on the pressure sensitive adhesive layer depending on necessity, and in use, after removing the release material in the case where the release material is provided, the general pressure sensitive adhesive sheet is attached to an adherend by making the pressure sensitive adhesive layer into contact therewith.
A pressure sensitive adhesive sheet having a large attaching area, which may be used for identification or decoration, masking for painting, surface protection of a metal plate or the like, and the like, has a problem that on attaching the sheet to an adherend, air accumulation is liable to occur between the pressure sensitive adhesive layer and the adherend, and the portion with the air accumulation is recognized as “blister”, so as to prevent the pressure sensitive adhesive sheet from being attached cleanly to the adherend.
For solving the problem, for example, PTL 1 describes a pressure sensitive adhesive sheet having grooves with a particular shape that are disposed artificially in a prescribed pattern on the surface of the pressure sensitive adhesive layer by making a release material having a fine emboss pattern into contact with the surface of the pressure sensitive adhesive layer.
There is described that, by using the pressure sensitive adhesive sheet, it is possible to escape the “air accumulation” formed on attaching to an adherend, to the exterior through the grooves formed artificially on the surface of the pressure sensitive adhesive layer.